[CI] Add USB tests to FPGA CI

[imphil]

Add tests to CI which utilize the USB peripheral on an FPGA board. See also https://github.com/lowRISC/opentitan/pull/4330

[alistair23]

Just a note that USB is still broken on the FPGA, see https://github.com/lowRISC/opentitan/issues/2598 and https://github.com/lowRISC/opentitan/issues/3388

[GregAC]

@a-will any thoughts on this?

[a-will]

The referenced issues are obsolete at this point, but it would definitely be nice to get CW310's OT USB devices hooked up in CI. Initially, we would likely reproduce the usbdev_test on FPGA (use the OT USB as a couple UARTs and send / receive data). We'll probably want more coverage at some point, though.

Tests will need the CW310 physically connected, and if the FPGA runner uses containers, we'll need to figure out a good strategy for passing through the devices. For the case of multiple boards connected to a single host, most likely the physical bus tree would need to be examined to associate FPGA USB devices with CW310 controller USB devices (so everything related to one board goes to the right place).

[alees24]

estimate 8

[moidx]

Moving to CI bucket

[drewmacrae]

Is this why the //sw/device/tests:usbdev_test_fpga_cw310_test_rom test fails when I run it, and should it be marked as broken or tagged to reflect an unfulfilled hardware requirement like we do for the jtag tests?

[alees24]

Is this why the //sw/device/tests:usbdev_test_fpga_cw310_test_rom test fails when I run it, and should it be marked as broken or tagged to reflect an unfulfilled hardware requirement like we do for the jtag tests?

It requires the DPI model and operates only in Verilator t-l simulation. The test is tagged as 'skip_in_ci' but I added the cw310_test_rom target because I do sometimes run it manually on FPGA. Is the 'skip_in_ci' tag incorrect or inadequate?

[a-will]

@drewmacrae For the FPGA variant to work, that test needs some host code to drive it--Specifically, it expects to see "Hi!Hi!" over the USB serial interface.

@alees24 Because that folder is intended for automated tests only, we should probably remove the target to avoid confusion. skip_in_ci only helps CI, but our teammates use these targets locally as well. Instead, perhaps consider using the very similar //sw/device/examples/hello_usbdev for non-automated purposes. We can add the FPGA target back once host code is available.

Edit: @cfrantz suggested that if we are planning to create that host code for this test, we can add the manual tag for now.

[alees24]

I'd prefer that it be tagged as manual then; I think usbdev_test serves as a useful smoke test and that it should become a usable regression test both in FPGA and in sim.

[johngt]

From @alees24 effort estimate 8 integration of t-l tests into CI, with host app <..8>

estimate 2